Device for cutting and retaining the weft threads in shuttleless looms

ABSTRACT

Device for cutting and holding weft threads in a shuttleless loom comprising two forklike plates, each with a groove for holding the weft thread, each groove having a lower edge defined by a cutting edge, two lever blades applied in articulation to said two plates and which present one of their ends bent in the shape of a hook, the upper inside edge of each hook being provided with a cutting edge, and drive means for imparting pivotal movement to said lever blades relative to said plates whereby weft threads which are disposed between the cutting edge in the grooves and the cutting edge on the hooks are cut by shearing action.

United States Patent Inventor Jose Bass: Bmrt Call: Bailen 150, Barcelona, Spain Appl. No. 838,753 Filed July 3, 1969 Patented Aug. 3, 1971 Priority July 6, 1968 Spain DEVICE FOR CUTTING AND RETAINING THE WEFT THREADS IN SHUTTLELESS LOOMS 6 Claims, 6 Drawing Figs.

Int. Cl ..D03d 47/34. D03d 45/50 Field of Search 139/122, 1,

Primary Examiner-J-lenry S. Jaudon All0rney-Cushman, Darby and Cushman ABSTRACT: Device for cutting and holding weft threads in a shuttleless loom comprising two forklike plates, each with a groove for holding the weft thread, each groove having a lower edge defined by a cutting edge, two lever blades applied in articulation to said two plates and which present one of their ends bent in the shape of a hook, the upper inside edge of each hook being provided with a cutting edge, and drive means for imparting pivotal movement to said lever blades relative to said plates whereby weft threads which are disposed between the cutting edge in the grooves and the cutting edge on the hooks are cut by shearing action.

Patented Aug. 3, 1971 3,596,585

2 Sheets-Sheet 1 Patented Aug. 3, 1971 3,596,685

2 Sheets-Sheet 2 DEVICE FOR CUTTING AND RETAINING THE WEFT THREADS IN SHUTTLELESS LOOMS The present invention relates to a device for cutting and holding weft threads in looms, in which the weft threads come from fixed bobbins located laterally outside the loom and pass through thread guides of a selector, said device holding selected weft threads in their position of presentation to the inserter elements to cut them, when they have been taken by the inserter elements.

In known cutting systems, in which shears are used to cut the weft threads, it is necessary to apply clamps to them adjacently, which hold the weft threads during the critical moment of cutting them. These clamps can hold the weft thread, even if it is rigid, but in this case, when the shears cut the thread, they can throw it out.

The inevitable application of clamps requires a precise synchronization between the clamps and the cutting device, all this in combination with the movement of the inserter element, whose synchronization complicates the machine, increasing the risks of wear and defects in the loom.

These drawbacks increase in case fabrics are made with different weft threads, in which one or more of these threads can be thick or some very delicate, the risk being that the clamps commonly used, when holding threads with different thickness at the same time, let some of the more delicate ones escape, which, in these cases, is solved by the application of two types of clamps, one for each thickness of weft thread. This drawback would increase in the case of looms that make two parallel fabrics at the same time, since for each fabric a cutting device and two clamps are required and synchronization of the two pairs of clamps with the pair of cutting devices is practically impossible.

These drawbacks are eliminated with the device for cutting and holding weft threads, the object of the present invention, since with it the application of weft thread clamps is totally eliminated and the device being able to be applied easily both to the fixed weft reserve looms that make only one fabric and to looms that make two parallel fabrics at the same time.

The device, the object of the present invention, is of very simple and economic design and consists of two forklike plates, with a groove for holding the weft threads, each one of these plates having in the lower edge of its groove a cutting edge, forming knives. In the lower branches of these forklike plates, are applied in articulation lever blades with an end bent in the shape of a hook, the upper inside edges of these hooks being provided with a cutting edge. The assemblies of sharpened lower edges of the grooves and the sharpened hooks form shears, by means of the union in articulation of the two lever blades by their other two ends which receive a vertical alternating back-and-forth movement coming from a single drive.

For a better understanding of the invention it is described below with reference to the accompanying drawings given by way of nonlimiting example:

FIG. 1 is a perspective view of the device mounted on a stationary shaft of a loom that makes two parallel fabrics at the same time.

FIG. 2 is a perspective view in perspective, on an enlarged scale, of the upper part of the device shown in FIG. 1.

FIG. 3 is a perspective view similar to that of FIG. 2, with a weft thread selected for each fabric and presented to its respective inserting element.

FIG. 4 is a perspective view similar to that of FIG. 3, but on an enlarged scale, with each selected weft thread taken by its corresponding inserting element.

FIG. 5 is a perspective view similar to that of FIG. 3, showing the difierent inserting elements in the position that they occupy a moment before cutting of the selected weft threads is performed.

FIG. 6 is a perspective view of a fraction of the upper part of the device, once the cutting of the selected weft threads has been performed.

In these Figures, there is represented at 1 a fixed shaft resting on bedframe 1 of the loom, to whose shaft 1 is attached a support 2 by a trunnion 3. The upper end of the support 2 defines a guide 6 by which a support piece 7 with a horizontal base 8 and slide 9 travel, said base 8 being united to the support 2 by a screw 10 that passes through slide 9. Support piece 7 has a vertical square-shaped wall 11 on which is attached a plate holder 12 by means of a screw 13 that passes through a vertical slide 14. Said plate holder 12 has slides 15 and 16 to 0 hold, by means of screws 17 and 18, forklike plate 19, and

slides 20 and 21 to hold, by means of screws 22 and 23, another plate 24, also forklike. These forklike plates 19 and 24 carry at pivot points 35 and 36, respectively, lever blades 27 and 28 having ends in the shape of hooks 31 and 32. The other ends of the blades 28 and 29 are connected at joints 37 and 38 by a linklike piece 39. At joint 38 is applied a rod 40 with threaded end 41, which by means of coupling sleeve 42, with its inside ends threaded in the opposite direction, which cannot be seen, joins said rod 40 to another rod 43 with threaded upper end 44, lower end 45 of rod 43 being connected to a trunnion 46 of arm 47 of a lever 48 of two arms 47 and 49, joined at point 50 to lower part 5 of support 2. Ann 47 supports a roller 51 that travels on a cam 52 applied to a mobile shaft 53 of the loom, not shown. 0n arm 49 of lever 48 is hooked end 54 of a helicoidal recoil spring 55, whose other end 56 is hooked to a projecting pivot 57 of support 2.

At the connection points 35 and 36 of lever blades 27 and 28 are applied helicoidal springs 58 and 59 which compress said lever blades 27 and 28 against plates 19 and 24.

The lower branches of plates 19 and 24 have cutting edges 60 and 61, and hooks 31 and 32 of lever blades 27 and 28 have cutting edges 62 and 63.

The operation is as follows:

Weft threads 64, 65, 66 and 67 corresponding to upper fabric 68, and weft threads 69, 70, 71 and 72 corresponding to the lower fabric, not shown, come from a weft selector, not shown, weft threads 64, 65, 66 and 67, before being united to upper fabric 68, being housed in groove 73 of plate 19 and weft threads 69, 70, 71 and 72, before being united to the lower fabric, being housed in groove 74 of plate 24, lever blades 27 and 28 not having yet moved into this position.

A weft thread presenter, not shown, has transferred selected weft threads 64 and 69 to bottoms 75 and 76 of hooks 31 and 32 of ends 29 and 30 of lever blades 27 and 28 (FIG. 3), selected weft threads 64 and 69 being presented and located opposite inserting elements 77 and 78 to be taken by these latter later (FIG. 4). At this moment, raising of ends 29 and 30 of lever blades 27 and 28 already having been performed by the turning of cam 52 which has made the assembly of rods 40 and 43 descend, shown only in FIG. 1, inserting elements 77 and 78 starting their return, selected weft threads 64 and 69 encircling hooks 31 and 32. From this moment, ends 29 and 30 in the shape of a hook 31 and 32 of lever blades 27 and 28 begin to go down in unison, weft thread 64 (FIG. 5) being located between cutting edge 62 of hook 31 and cutting wire 60 of plate 19, and weft thread 69 at the same time is located between cutting edge 63 of hook 32 and cutting edge 61 plate 24. Therefore, weft threads 64 and 69 (FIG. 6) are cut by cutting edges 62 and 63 which act as shears with cutting wires 60 and 61.

Constructive details and characteristics used in the practice of the invention may be modified without departing from the scope of the invention.

Iclaim:

1. Device for cutting and holding weft threads in a shuttleless loom comprising two forklike plates, each with a groove for holding the weft thread, each groove having a lower edge defined by a cutting edge, two lever blades applied in articulation to said two plates and which present one of their ends bent in the shape of a hook, the upper inside edge of each hook being provided with a cutting edge, and drive means for imparting pivotal movement to said lever blades relative to said plates whereby weft threads which are disposed between the cutting edge in the grooves and the cutting edge on the hooks are cut by shearing action.

2. A device for cutting weft threads as in claim 1 including a helicoidal compression spring disposed at the point of articulation between each plate and each lever blade, said spring pressing the lever blade against the respective plate.

3. A device for cutting weft threads as in claim 1 including a linklike piece pivotally connected between the ends of said lever blade which are opposite the hooked ends thereof, a drive rod having one end connected to said linklike piece and another end connected to a trunnion which is solid with a lever arm, and a cam for imparting pivotal motion to said lever arm.

4. A device for cutting weft threads as in claim 1 wherein said lever arm carries a roller which engages said cam, said device further including spring means biasing said lever arm in a direction to maintain said roller in engagement with said cam.

5. A device for cutting weft threads as in claim 1 including a plate holder, means for adjustably mounting said plates in a variety of horizontal positions relative to said plate holder, a holder support, and means for adjustably mounting said plate holder in a variety of vertical positions relative to said holder support.

6. A device for cutting weft threads as in claim 5 including a fixed assembly support having an upper portion defining a horizontal slide, said holder support being adjustably mounted on said horizontal slide. 

1. Device for cutting and holding weft threads in a shuttleless loom comprising two forklike plates, each with a groove for holding the weft thread, each groove having a lower edge defined by a cutting edge, two lever blades applied in articulation to said two plates and which present one of their ends bent in the shape of a hook, the upper inside edge of each hook being provided with a cutting edge, and drive means for imparting pivotal movement to said lever blades relative to said plates whereby weft threads which are disposed between the cutting edge in the grooves and the cutting edge on the hooks are cut by shearing action.
 2. A device for cutting weft threads as in claim 1 including a helicoidal compression spring disposed at the point of articulation between each plate and each lever blade, said spring pressing the lever blade against the respective plate.
 3. A device for cutting weft threads as in claim 1 including a linklike piece pivotally connected between the ends of said lever blade which are opposite the hooked ends thereof, a drive rod having one end connected to said linklike piece and another end connected to a trunnion which is solid with a lever arm, and a cam for imparting pivotal motion to said lever arm.
 4. A device for cutting weft threads as in claim 1 wherein said lever arm carries a roller which engages said cam, said device further including spring means biasing said lever arm in a direction to maintain said roller in engagement with said cam.
 5. A device for cutting weft threads as in claim 1 including a plate holder, means for adjustably mounting said plates in a variety of horizontal positions relative to said plate holder, a holder support, and means for adjustably mounting said plate holder in a variety of vertical positions relative to said holder support.
 6. A device for cutting weft threads as in claim 5 including a fixed assembly support having an upper portion defining a horizontal slide, said holder support being adjustably mounted on said horizontal slide. 